PREOPERATIVE EVALUATION OF GASTRIC CARCINOMA BY MAGNETIC RESONANCE IMAGING

Abstract

BACKGROUND: Gastric carcinoma is the fourth most common cancer and the second leading cause of cancer-related deaths. Tumor staging and classification often require a combination of immunohistochemical tests with radiological imaging. The use of MRI for preoperative staging of gastric cancer has become a predominant focus in recent years.

OBJECTIVE: To evaluate the efficiency of MRI as a diagnostic tool for preoperatively evaluating the stage of gastric cancer vis-a-vis post- operative pathological staging.

STUDY DESIGN: The study was comparative in nature.

PARTICIPANTS: Initially 37 patients of recently diagnosed gastric adenocarcinoma were taken in our study, however, 13 patients were excluded as they were subjected to neoadjuvant chemoradiotherapy. The remaining 24 patients became the sample size of our study.

METHODS:  Preoperative MRI study of the patients was performed on 1.5T MRI scanner after patient preparation that included patient fasting for six hours, gastric distension by drinking water prior to the examination and administration of 10ml of intramuscular hyoscine butyl-bromide. MR imaging T stage was correlated with the corresponding pathological T stage.

RESULTS: The MRI diagnostic accuracy of T1 stage was 87.5% with a specificity of 94.7% and sensitivity of 60% (k value =0.58). The MRI diagnostic accuracy of T2 stage was 87.5%, with a specificity of 88.2 % and sensitivity of 85.7% (k value=0.69). The MRI diagnostic accuracy for T3 stage was 91.7 % with a specificity of 93.3% and sensitivity of 88.9% (k value=0.82). The diagnostic accuracy for T4 stage stood at 95.8% with a specificity of 100 % and sensitivity of 75 % (k value=0.80).

CONCLUSION: We concluded from our study that MRI could prove an excellent diagnostic modality in the local staging of gastric cancer due to its high accuracy and specificity in determining the depth of invasion.

IMPLICATIONS: MRI can be a useful imaging modality in preoperative local staging of gastric adenocarcinoma particularly in pregnant females and those having severe hypersensitivity to iodinated CT contrast agents.